Class, who wants to explain this one?

I've encountered this many, many times in the 20 years of playing D2, but I've never seen it explained.
Why do bosses sometimes roll the same item twice, on the same kill, and also roll both as uniques?
Then, since the same unique can't drop twice in the same game, it rolls it as a set, and when no such set exists, it ultimately drops a unique and a failed set.
I remember my astonishment as a kid, 20-ish years ago, when NM Diablo dropped an Oculus and a

Tal Rasha's Lidless Eye at the same time.

Anyway, anybody got anything to share with the class?

P.S. Oh, right.

War Fork has a durability of 28.

I'm not sure if it's possible to give an answer as to why this happens, but I believe the explanation is that this is a quirk of the game's "pick" system. Most normal monsters have only one "pick" to drop from (and we know that this can roll a NoDrop), but bosses have multiple picks that can be selected - Hell Meph has 7 picks from his Act 4 "H" treasure class, for instance. In this scenario, I assume there was at least two picks that attempted to generate from the same TC, but may not have rolled a similar rarity. From what I remember, blue items with double durability are failed Sets, and yellows with triple durability are failed Uniques.

So, the game went from Unique (fail) -> Set (success) -> no Set variant exists -> double durability blue.

Because item rolls are sequential and independent of one another. As a result, when a boss (or any mob that can drop more than 1 item) is killed, there's a chance for them to roll the same base item more than once. Each of those rolls then has a chance to roll unique. If both do, the second one is automatically downgraded because the unique was already used/blocked for the game by the first roll, resulting in what you see here.

Not exactly a common occurrence but to be expected every so often, given loot generation mechanics.

I believe the simpler answer is that the game really forked you on that Diablo drop.

Yeah, that was terrible. I'm sorry. I'll go wait in the car.

@Khegan @Schnorki Okay, so nothing I didn't already know or explain in my post.

iamergo wrote: 2 years ago

@Khegan @Schnorki Okay, so nothing I didn't already know or explain in my post.

Still nice to see some elaboration on how the mechanics work. Unless someone wants to dive into the code and find the 'why' I'm not sure if this could be explored in a better way.

Teebling wrote: 2 years ago

Still nice to see some elaboration on how the mechanics work. Unless someone wants to dive into the code and find the 'why' I'm not sure if this could be explored in a better way.

Yeah, but again, I already knew everything they said and even explained the gist of it. I thought maybe somebody had already dived into the code and could enlighten me. Alas.

Phrozen Keep is the place to check out if you’re looking for dedicated data/code miners. Sadly, I don’t have the means to access the code myself.